Automotive electrochromic mirror reflective element cell assemblies typically include a front substrate and a rear substrate and an electrochromic medium sandwiched therebetween and contained within an interpane cavity. The substrates are shaped as desired by the automobile manufacturer for a particular mirror design or application. Reflective element assemblies for exterior rearview mirror assemblies may include an auxiliary wide angle or spotter mirror portion, such as the types described in U.S. Pat. Nos. 7,255,451; 7,195,381; 6,717,712; 7,126,456; 6,315,419; 7,097,312; 6,522,451; 6,315,419; 5,080,492; 5,050,977; and/or 5,033,835, which are hereby incorporated herein by reference in their entireties, and optionally may have an integrally formed auxiliary mirror reflector, such as the types described in U.S. Pat. Nos. 8,021,005; 7,934,844; 7,887,204; 7,824,045; and 7,748,856, which are hereby incorporated herein by reference in their entireties.
During manufacture and assembly of an electrochromic reflective element cell, the desired shape of the respective front and rear substrates are typically scribed (using the likes of a diamond tipped scriber or the like) onto a larger flat or curved glass sheet or lite. Often, multiple shapes are scribed into a single large glass sheet, and, after the shapes have been scribed, individual cut shapes/substrates are broken out from the scribed glass sheet or lite in a known manner. Since breaking out of a shape is most efficient or effective where the breakout line does not have sharp or convoluted turns or radii, it is desirable that the front and rear cut shapes or substrates to be used in an electrochromic mirror cell not have sharp or convoluted corners or radii, and that they generally each be of comparable or similar size, shape and dimension. After breakout, the individual front and rear cut shapes or substrates are cleaned and coated with a conductive or semiconductive coating or coatings that are reflective or transparent.
After the substrates are coated, an uncured adhesive material, typically an uncured epoxy material (often containing spacer beads, such as glass beads or the like), is precision dispensed around the perimeter of one of the cut shapes or substrates, and the other cut shape or substrate is superimposed thereupon and spaced apart from the first cut shape by the dispensed perimeter material. The uncured adhesive material (i.e., the uncured seal) is then cured, such as by heating, to form a cured seal that adheres the shapes or substrates together and that spaces the substrates apart a desired or appropriate or selected amount to define and establish an appropriate interpane cavity spacing. The substrates, when so adhered together and interspaced apart by the cured seal, form an empty cell with an interpane cavity between the substrates and bounded by the perimeter cured seal. Next, an electrochromic medium, such as an electrochemichromic fluid or an electrochromic monomer composition, is filled into the cavity via an aperture (commonly known as a fill port or plug hole) provided in the cured perimeter seal during its dispensing. Filling is typically via a vacuum fill process (such as described in U.S. Pat. No. 5,140,455, which is hereby incorporated herein by reference in its entirety), and the fill port is plugged or sealed with a suitable plug material to complete the isolation of the electrochromic medium established in the interpane cavity of the reflective element or cell to protect against infiltration by outside air and against contamination by the likes of outside water or debris or the like.